给定一棵树,以及所有节点的权重(以字符串的形式),任务是计算加权字符串是具有给定字符串str的字谜的节点。
例子:
Input:
str = “geek”
Output: 2
Only the weighted strings of the nodes 2 and 6
are anagrams of the given string “geek”.
方法:在树上执行 dfs,对于每个节点,检查它的加权字符串是否与给定的字符串是 anagram,如果不是,则增加计数。
下面是上述方法的实现:
C++
// C++ implementation of the approach
#include
using namespace std;
string s;
int cnt = 0;
vector graph[100];
vector weight(100);
// Function that return true if both
// the strings are anagram of each other
bool anagram(string x, string s)
{
sort(x.begin(), x.end());
sort(s.begin(), s.end());
if (x == s)
return true;
else
return false;
}
// Function to perform dfs
void dfs(int node, int parent)
{
// If current node's weighted
// string is an anagram of
// the given string s
if (anagram(weight[node], s))
cnt += 1;
for (int to : graph[node]) {
if (to == parent)
continue;
dfs(to, node);
}
}
// Driver code
int main()
{
s = "geek";
// Weights of the nodes
weight[1] = "eeggk";
weight[2] = "geek";
weight[3] = "gekrt";
weight[4] = "tree";
weight[5] = "eetr";
weight[6] = "egek";
// Edges of the tree
graph[1].push_back(2);
graph[2].push_back(3);
graph[2].push_back(4);
graph[1].push_back(5);
graph[5].push_back(6);
dfs(1, 1);
cout << cnt;
return 0;
}
Java
// Java implementation of the approach
import java.util.*;
class GFG
{
static String s;
static int cnt = 0;
static Vector[] graph = new Vector[100];
static String[] weight = new String[100];
// Function that return true if both
// the Strings are anagram of each other
static boolean anagram(String x, String s)
{
x = sort(x);
s = sort(s);
if (x.equals(s))
return true;
else
return false;
}
static String sort(String inputString)
{
// convert input string to char array
char tempArray[] = inputString.toCharArray();
// sort tempArray
Arrays.sort(tempArray);
// return new sorted string
return new String(tempArray);
}
// Function to perform dfs
static void dfs(int node, int parent)
{
// If current node's weighted
// String is an anagram of
// the given String s
if (anagram(weight[node], s))
cnt += 1;
for (int to : graph[node])
{
if (to == parent)
continue;
dfs(to, node);
}
}
// Driver code
public static void main(String[] args)
{
s = "geek";
for (int i = 0; i < 100; i++)
graph[i] = new Vector();
// Weights of the nodes
weight[1] = "eeggk";
weight[2] = "geek";
weight[3] = "gekrt";
weight[4] = "tree";
weight[5] = "eetr";
weight[6] = "egek";
// Edges of the tree
graph[1].add(2);
graph[2].add(3);
graph[2].add(4);
graph[1].add(5);
graph[5].add(6);
dfs(1, 1);
System.out.print(cnt);
}
}
// This code is contributed by Rajput-Ji
Python3
# Python3 implementation of the approach
cnt = 0
graph = [[] for i in range(100)]
weight = [0] * 100
# Function that return true if both
# the strings are anagram of each other
def anagram(x, s):
x = sorted(list(x))
s = sorted(list(s))
if (x == s):
return True
else:
return False
# Function to perform dfs
def dfs(node, parent):
global cnt, s
# If weight of the current node
# string is an anagram of
# the given string s
if (anagram(weight[node], s)):
cnt += 1
for to in graph[node]:
if (to == parent):
continue
dfs(to, node)
# Driver code
s = "geek"
# Weights of the nodes
weight[1] = "eeggk"
weight[2] = "geek"
weight[3] = "gekrt"
weight[4] = "tree"
weight[5] = "eetr"
weight[6] = "egek"
# Edges of the tree
graph[1].append(2)
graph[2].append(3)
graph[2].append(4)
graph[1].append(5)
graph[5].append(6)
dfs(1, 1)
print(cnt)
# This code is contributed by SHUBHAMSINGH10
C#
// C# implementation of the approach
using System;
using System.Collections.Generic;
class GFG
{
static String s;
static int cnt = 0;
static List[] graph = new List[100];
static String[] weight = new String[100];
// Function that return true if both
// the Strings are anagram of each other
static bool anagram(String x, String s)
{
x = sort(x);
s = sort(s);
if (x.Equals(s))
return true;
else
return false;
}
static String sort(String inputString)
{
// convert input string to char array
char []tempArray = inputString.ToCharArray();
// sort tempArray
Array.Sort(tempArray);
// return new sorted string
return new String(tempArray);
}
// Function to perform dfs
static void dfs(int node, int parent)
{
// If current node's weighted
// String is an anagram of
// the given String s
if (anagram(weight[node], s))
cnt += 1;
foreach (int to in graph[node])
{
if (to == parent)
continue;
dfs(to, node);
}
}
// Driver code
public static void Main(String[] args)
{
s = "geek";
for (int i = 0; i < 100; i++)
graph[i] = new List();
// Weights of the nodes
weight[1] = "eeggk";
weight[2] = "geek";
weight[3] = "gekrt";
weight[4] = "tree";
weight[5] = "eetr";
weight[6] = "egek";
// Edges of the tree
graph[1].Add(2);
graph[2].Add(3);
graph[2].Add(4);
graph[1].Add(5);
graph[5].Add(6);
dfs(1, 1);
Console.Write(cnt);
}
}
// This code is contributed by PrinciRaj1992
Javascript
输出:
2
复杂度分析:
- 时间复杂度: O(N*(S*log(S)))。
在 dfs 中,树的每个节点都被处理一次,因此如果树中总共有 N 个节点,则由于 dfs 的复杂性是 O(N)。此外,为了处理每个节点,使用 sort()函数,其复杂度为 O(S*log(S)),其中 S 是加权字符串的长度。因此,时间复杂度为 O(N*(S*log(S))),其中 S 是树中权重字符串的最大长度。 - 辅助空间: O(1)。
不需要任何额外的空间,因此空间复杂度是恒定的。
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